最佳水質指標選擇之研究

Comparison Study of the Best Water Quality Index

陳鴻烈(Paris Honglay Chen) ； 蔡大偉(David D. W. Tsai) ； 呂銘淵(Ming-Yuan Lu)

《農林學報》 58卷2期 (2009/06) Pp. 145-162

https://doi.org/10.30089/JAF.200906.0006

摘要

本研究主要目的在於探討最佳水質指標，以協助集水區水質管理策略之訂定與監測。研究中選用淡水河流域為研究區域，在蒐集水質資料後，依地理位置切割為上、中、下游三區，三區之平均值視為可代表整體流域。研究透過敘述統計，分析各區16項水質參數與RPI(River Pollution Index)、WQI(Water Quality Index)兩種水質指標，藉此了解水質狀況，並依據分析結果來評斷水質指標之優缺點。研究結果顯示淡水河整體而言遭受嚴重污染，且以人口最集中之中游區最為嚴重，上游翡翠水庫區相對而言污染程度較輕，下游區則因海水稀釋作用，污染情形介於兩者之間。根據敘述統計結果，WQI對水質污染敏感度優於RPI，於污染較輕的上游區仍可明顯反應出有遭受污染的情形，RPI則否，因此根據本研究量化數據指出，WQI優於RPI，建議未來進行集水區水質管理時，能將WQI納入優先考量之水質指標。

關鍵字

RPI ； WQI ； 敘述統計 ； 集水區管理

並列摘要

The main purpose of this study was to find out the best water quality index which could be helpful for monitoring and decision-making in watershed management. We selected the Dansuie River Watershed as a study site and collected all available water quality data. The watershed was separated into three groups according to geographical location: up, middle and downstream. The mean of those three data was used to represent the whole watershed. Sixteen water quality factors and two water quality indexes, RPI and WQI, were analyzed by descriptive statistics. The results could help us to understand water quality conditions in the river and to evaluate two water quality indexes. We find out several problems in Dansuie River: (1) The most serious pollution occurred in the middle stream. (2) The upstream including Feitsui Reservoir had better water quality. And (3) The water quality of downstream lay between the up and middle stream owing to the dilution effect of ocean. Comparing the indexes, WQI offered better sensitivity than RPI. Especially in the upstream, WQI could detect light pollution, but RPI cannot. Therefore, WQI is a better index for water quality management.

並列關鍵字

RPI ； WQI ； Descriptive statistics ； Watershed management